Adipose-derived stromal/stem cells (ASCs) pose exciting opportunities for the field of biomedical engineering. ASCs are attractive as a cell source for tissue regeneration procedures because of their ready availability and limited donor-site morbidity. Past research has shown that these cells can be differentiated into a variety of cell types using media supplements, effectively guiding them towards specific lineages of interest;chondrocytic, osteoblastic, and adipocytic. Current studies in our laboratory indicate that fully differentiated cells and undifferentiated ASCs possess biomechanical properties characteristic of their cell type (i.e. chondrocyte, osteoblast, adipocyte). The goal of the Independent Phase of this Award is to separate ceiis within lipoaspirate by their biomechanical properties to produce lineage-specific cell sources that will improve the functional performance of engineered tissues. We hypothesize that engineered constructs containing a higher percentage of tissue-specific stem ceils wili possess better biomechanical and biochemical properties than constructs seeded with a more heterogeneous harvest population. To test this, we will sort ceils from liposuction waste tissue by their biomechanical properties and subsequently evaluate their multipotent character. Concurrent with these studies, we will design and fabricate a device capable of sorting large numbers of cells based on their mechanical characteristics. The resulting subpopulations will possess measurable distributions of mechanical properties, which are hypothesized to indicate an ASCs ability to differentiate down different mesenchymal lineages. Tissue engineered cartilage constructs will then be grown using either heterogeneous and mechanicaiiy-sorted cell populations to determine how stem ceil enrichment affects the quality of tissue formation. The entire proposed project will produce significant advances in the areas of mechanotransduction, stem cell biology, and tissue engineering.